1. Field of the Invention
The present invention relates to a portable terminal apparatus such as a mobile phone handset and a display module which is mounted on the portable terminal apparatus or the like to display an image.
2. Description of the Related Art
A portable terminal apparatus in recent years is additionally provided with an image display function, and liquid crystals, organic EL (Electro Luminescence), or the like is used in its display device. Glass is generally used for such a display device. Since a portable terminal apparatus is a device to be carried around by a person, an external force such as a strong compressive force or an impactive force is frequently applied to the portable terminal apparatus during use. However, a glass which is used for a display device is sensitive to an external force, and a glass breakage may occur, causing a display problem.
Typically, in a portable terminal apparatus, a display device is reinforced and fixed by a chassis structure. From a structural viewpoint, a glass breakage in the display device is often caused by an external force in a direction of the display surface. An external force causes a chassis to bend, and a glass edge interferes with the chassis, thereby causing a glass breakage. Japanese Patent Laid-Open No. 2000-307258 discloses a housing structure which is aimed at solving the problem and is hard to break even if an external force is applied.
In a portable terminal apparatus, an integrated circuit component which operates at a high frequency is packaged on an electrical component. It is necessary for the portable terminal apparatus to avoid the influence of radiation noise generated from the integrated circuit component and the like. Japanese Patent Laid-Open No. 2005-19850 discloses an electromagnetic interference shielding structure for avoiding the influence of radiation noise and the like.
FIG. 6 is an exploded perspective view showing the structure of a conventional display module intended to prevent a glass breakage upon application of an external force and avoid the influence of radiation noise and the like.
A display module 100 shown in FIG. 6 is composed of a display board 110 on which an EL display element displaying an image is mounted and which is made of a glass material, a chassis 120 which is made of a resin material such as ABS, and a sheet metal component 130 which is made of a metal material.
The chassis 120 is formed of a support board 121 which supports the display board 110 and a frame plate 122 which surrounds the support board 121 to support it. In the chassis 120, openings 123 vertically extending between the support board 121 and the frame plate 122 are formed at portions which correspond to the four corner sections of the display board 110 when the display board 110 is placed on the support board 121.
The chassis 120 is configured such that the support board 121 bends to absorb an external force when the external force is applied to the display board 110, and the display board 110 is pressed. If the support board 121 expands so as to fill the openings 123 in the four corners, the support board 121 may interfere with the display board 110 at the four corners to cause a glass breakage in the display board 110. In this arrangement, the openings 123 are formed in the four corners to avoid such a breakage. The provision of these openings 123 prevents a glass breakage even if an external force is applied.
A notch section 124 is formed in a part of the frame plate 122 of the chassis 120. A flexible board (not shown) extending from the display board 110 passes through the notch section 124.
The sheet metal component 130 has the shape of a box facing downward. The shape will be described with reference to parts (A) and (B) of FIG. 7.
Parts (A) and (B) of FIG. 7 are sectional views, respectively, taken along arrows X1-X1 and X2-X2 shown in FIG. 6. For illustrative convenience, in FIG. 6, the arrows X1-X1 and X2-X2 indicate the positions of sections of the chassis 120. Parts (A) and (B) of FIG. 7 show the structures of the sections, including the display board 110 and sheet metal component 130, at the positions corresponding to the arrows X1-X1 and X2-X2.
Part (A) of FIG. 7 is a sectional view taken along the arrow X1-X1 shown in FIG. 6; and part (B) of FIG. 7, a sectional view taken along the arrow X2-X2 shown in FIG. 6.
The frame plate 122 of the chassis 120 is placed on a circuit board 300 while supporting the support board 121 at a predetermined height with respect to the circuit board 300. The sheet metal component 130 has the shape of a box facing downward, as shown in parts (A) and (B) of FIG. 7. The sheet metal component 130 is fit in a portion delimited by the frame plate 122 and the back surface of the support board 121 of the chassis 120 and is placed on the circuit board 300 together with the frame plate 122. The sheet metal component 130 is connected to electrical ground on the circuit board 300 through a structure (not shown). A circuit component 310 such as an IC chip is mounted at a portion, opposing the center of the support board 121, of the circuit board 300. The sheet metal component 130 connected to ground surrounds the circuit component 310 to give the shielding effect to the circuit component 310. This arrangement prevents radiation noise and the like from the circuit component 310 from leaking outside.
Part (B) of FIG. 7 also shows the openings 123 described with reference to FIG. 6. As described above, with the presence of these openings 123, no interference occurs between the corner sections of the display board 110 and the support board 121 even if an external force is applied to the display board 110, and the support board 121 bends. This prevents the occurrence of a glass breakage in the display board 110.
Conventionally, the display module 100 with the structure shown in FIG. 6 and parts (A) and (B) of FIG. 7 is adopted as an example. However, it is desired to further promote a reduction in weight and the number of components, and the like demanded of a portable terminal apparatus.